A known safety valve of this type includes a main body having a gas channel and a valve port formed at a downstream end thereof, a valve body biased in the direction to close the valve port, an attracting part that attracts the valve body by an electromagnetic force, and an electric drive mechanism such as a motor that makes the attracting part move back and forth in the valve closing direction and the valve opening direction (for example, see Patent Literature 1).
With this safety valve, the electric drive mechanism is energized and activated to move the attracting part in the valve closing direction until the attracting part abuts against the valve body, and then, in a state where the valve body is attracted to the attracting part producing magnetic force, the electric drive mechanism moves the attracting part back in the valve opening direction to open the gas channel. If the magnetic force of the attracting part attracting the valve body is maintained by supplying electric power to the safety valve, the gas channel is kept open.
When the energization of the safety valve is stopped, the magnetic force of the attracting part disappears, and the safety valve becomes the closed-state by the biasing force applied to the valve body.